The outcome of patients with tSAH at admission is related in a logistic regression analysis to the admission Glasgow Coma Scale score and to the amount of subarachnoid blood. These patients also have a significant risk of CT progression. The amount of subarachnoid blood and the presence of associated parenchymal damage are powerful independent factors associated with CT progression, thus linking poor outcomes and CT changes.

No abstract

SummaryRhabdomyolysis during routine surgery was studied in three groups of patients who had surgery, with limited trauma to muscle, in the lateral and supine positions, and prone on the spinal frame. A range of blood tests was performed (before surgery, and on the jirst, third and seventh day after operation). These showed that a creatine kinase increase in the 24 hours and the early appearance of myoglobin in the serum were the best indicators. Rhabdomyolysis was associated with the lateral position and long lasting surgery. No blood test before surgery was of any predictive value.

There was little correlation between CPP values and global cerebral blood flow levels in our selected patients, probably because pressure autoregulation was preserved. Global metabolism measurements were constant within the groups, suggesting that in patients with controlled physiological variables an interplay between cerebral blood flow and metabolism might be more relevant than the relationship between CPP and cerebral blood flow.

Cerebral blood flow (CBF) alterations following post-traumatic contusions have been demonstrated in recent papers. We evaluated regional CBF (rCBF) by means of Xenon-enhanced computerized tomography (Xe-CT) in 29 traumatic intracerebral hematomas, from 22 patients with severe head injury (GCS < or = 8). Fifty traumatic hematoma/Xe-CT CBF measurements were obtained from 39 Xe-CT studies performed during the acute phase (corresponding to the first 20 days post-injury). The rCBF was measured in three different regions of interest: the hemorrhagic core, the perihematoma edematous low-density area, and a 1-cm rim of perihematoma normal-appearing brain tissue, surrounding the edematous low-density area. We found a centrifugal improvement of rCBF as well as a decrease in the rates of CBF levels below 18 mL/100 g/min from the core to the periphery (p < 0.0001), which persisted over time. Ischemic rCBF values were detected in the perihematoma low-density area only in 24% of the traumatic hematomas. The time course of rCBF levels showed a reduced flow in the first 24 h, with a recovery of flow from day 2 to day 4, followed by another reduced flow (p < or = 0.0001) both in the perihematoma edematous low-density area and in the non-lesioned tissue. Our findings suggest that the only area with persistent ischemic values was the hemorrhagic core. Low rCBF levels seen in the perihematoma low-density area may only be ascribed partially to ischemia and can possibly recover over time. These results could encourage a surgical approach based on an early evacuation of the hemorrhagic core associated to a preservation of the surrounding edematous tissue.

No abstract

Our findings suggest that CPP elevation induced by norepinephrine is effective in improving contusional rCBF only in selected cases, which are represented by a subset of contusions with critical perfusion, which can be identified by rCBF measurements. Conversely, in contusions with rCBF higher than critical low values, the CPP elevation could probably induce a temporary breakdown of the blood brain barrier, and the norepinephrine leads to a vasoconstriction with a worsening of regional perfusion.

Arterio-venous pCO2 difference (AVDpCO2) and estimated respiratory quotient, the ratio between AVDpCO2 and arterio-venous O2 difference, may be potentially useful estimators of irreversible posttraumatic global cerebral ischemia. Our aim was to evaluate their relevance, along with arterio-venous lactate difference (AVDL) and lactate oxygen index (LOI), in early outcome prediction. The retrospective study involved 55 patients with severe head injury, admitted consecutively in a multidisciplinary intensive care unit of a general hospital. A retrograde jugular catheter was placed as soon as possible, allowing for 324 simultaneous arterio-jugular samples to be taken throughout the first 48-hour postinjury. Early brain death (within 48 h) was assumed to be due to early global ischemia. A multivariate model including clinical and radiologic descriptors and jugular bulb variables showed that a widening of AVDL and LOI was associated with early brain death. Whereas in the patients who died, a progressive worsening of AVDpCO2 and estimated respiratory quotient, associated with corresponding changes in AVDL and LOI were observed, in patients who survived the widening of AVDpCO2 normalized along with that of arterio-venous O2 difference. These findings suggest that the isolated measurement of widening AVDpCO2 is not specific for global cerebral ischemia, but its observation over time could be potentially more useful.